Stephen Hawking’s Final Paper Was Just Released

Stephen Hawking’s final paper was just published by his colleagues in the pre-print journal arXiv. The team had completed the research a few days before Hawking’s death in March.

It was the third in a series of papers that dealt with a concept Hawking spent decades pondering: the black hole information paradox. Here’s how it goes:

Black holes are extremely dense, time-space-warping objects that can form when stars collide or giant stars collapse in on themselves. Classical physics suggests that nothing could escape a black hole, even light. But in the 1970s, Hawking proposed that black holes might have a temperature and could slowly leak out quantum particles. This “Hawking radiation” effect means that, eventually, the black hole will evaporate, leaving behind a vacuum that will look the same for each evaporated black hole, no matter what it ate during its lifetime.

This idea posed a problem: During its lifetime, the black hole swallowed a lot of information in the form of celestial objects, but where did that information go? The laws of physics dictate that no information should be lost: If information existed in the past, we should be able to recover it. Hence, the paradox.